The Chung Yeung Festival (Double Ninth Festival) is a traditional Chinese holiday celebrated on the ninth day of the ninth lunar month. It is observed as a public holiday in Hong Kong and Macau and widely celebrated in mainland China and Taiwan.

The festival is directly related to the philosophical concept of yin and yang, two interconnected aspects that symbolize dark and light, night and day, the moon and the sun, femininity and masculinity, earth and sky, water and fire, accordingly.

According to Chinese tradition, nine is a yang number. The double nine (i.e. the 9th day of the 9th month in the Chinese calendar) has too much yang, which is potentially dangerous. Hence, it is customary to perform special rituals that help avoid danger. One can climb a mountain, drink chrysanthemum wine or tea, or wear Cornelian cherry (zhuyu). Cornelian cherry and chrysanthemum are believed to have cleansing and protecting qualities.

In China and Hong Kong, many people visit ancestral graves to pay their respects to the deceased. They clean the grave, leave food offerings, and burn incense sticks. In Taiwan, the Double Ninth Festivals is also known as Senior Citizens' Day. On this day, citizens of Taiwan demonstrate their care for and appreciation of the elderly.